Abstract Dual-frequency laser Interferometer adopts heterodyne interference measurement principle。It has lots of advantages,like low noise,anti-environment interference,allowing light source multiplexing channels and so on。IDual-frequency laser Interferometer is one of the current high-precision,large measurement range,ultraprecise length measuring instrument。In displacement measurement with nanoscale or sub-nanometer,Dual-frequency laser Interferometer is widespread used for sophisticated manufacturing and measurement area,like semiconductor fabrication,high-grade control machine tool and so on。
Dual-frequency laser Interferometer especially plays a very important role in ultra precision Dynamic displacement measurement with Nano-resolution。It is a core sensor,which can achieve the ultra precision kinematics accuracy of six-freedom motion platform to feedback。This paper ,according to the 《graduation project mandate》,complete the relevant design and planning work of the signal processing module ,based on VPX-backplane bus, and the HSSL optical Fiber and EtherCat high speed transmission verification module,based on PCIX-bus,of Dual-frequency laser Interferometer。
This paper designs and completes the project functional requirement specification。This specification is for project designer and software developer to use。It plans the various functional requirements,performance index of Dual-frequency laser Interferometer,like rang limit,sampling period and so on,in detail。 This specification provides the evidence for the following project developing steps,like project circuit design,software programming;provides the standard for the checking of system functions and performances。
This paper designs the high-speed transport protocol。Transport protocol is in units of frames。Serial communication protocol has two kinds of frames,included:PC—>counting card command frame(CmdFM) ,counting card—>PC response frame(ResFM)。CmdFM is based on frameNumber as a difference to make commands to counting card like reading,change,save settings。According to the trotocol,ResFM make the corresponding actions to response the CmdFM。HSSL optical fibre transmission communication protocol has three kinds of frames,included:PC—>counting card trigger frame(TTC-FM),PC—>counting card response frame(ATC-FM),counting card—>PC data